, 2
Section A
You should spend a maximum of 40 minutes on this section.
Write your answer to each question in the box provided.
1 Part of a protein structure can be represented as:
–CONHCH(CH3)CONHCH2CONHCH(CH3)–
What is correct about this part of the protein structure?
A All its amino acids show optical isomerism.
B It has three peptide links.
C It is an addition polymer.
D It is made from three different amino acids.
Your answer [1]
2 What is correct about the greenhouse effect?
A Greenhouse gas bonds vibrate more when warmed by infrared radiation.
B Greenhouse gases reflect infrared radiation back to Earth.
C The Earth emits mostly ultraviolet radiation.
D The principal radiation from the Sun is infrared.
Your answer [1]
3 An organic compound A is oxidised to a different compound which forms a silver mirror with Tollens’
reagent.
Which could be compound A?
A propanal
B propan-1-ol
C propan-2-ol
D propanone
Your answer [1]
© OCR 2025
, 3
4 Which statement about transition metals is correct?
A Copper(II) ions form an octahedral complex with chloride ions.
B Most manganese compounds have Mn in the oxidation state of +2, +4 or +7.
C Nickel is used as a catalyst in the hydration of alkenes.
D The dichromate ion is often used as a reducing agent.
Your answer [1]
5 Which statement about the element astatine, At, is likely to be correct?
A It displaces iodine from sodium iodide.
B It is a gas at room temperature.
C It is a weaker oxidising agent than chlorine.
D It is colourless.
Your answer [1]
6 Which of the following pairs can be structural isomers?
A acid anhydrides and aldehydes
B amines and amides
C carboxylic acids and esters
D diols and esters
Your answer [1]
7 Which row shows the correct electron configurations of Cr and Cr3+?
Cr Cr3+
A [Ar] 3d4 4s2 [Ar] 3d3
B [Ar] 3d4 4s2 [Ar] 3d1 4s2
C [Ar] 3d5 4s1 [Ar] 3d3
D [Ar] 3d5 4s1 [Ar] 3d1 4s2
Your answer [1]
© OCR 2025 Turn over
, 4
8 What is an advantage of both ethanol and hydrogen as alternatives to petrol?
A Their only product of combustion is water.
B They can be produced by fermentation.
C They do not produce nitrogen oxides in the engine.
D They do not produce oxides of sulfur on combustion.
Your answer [1]
9 What is correct about chlorine radicals in the atmosphere?
A They act as homogeneous catalysts that increase ozone depletion.
B They are formed by heterolytic fission of CFCs.
C They are formed by homolytic fission of CFCs by infrared radiation.
D They are heterogeneous catalysts that increase the rate of ozone formation.
Your answer [1]
10 A colorimeter is used to measure the concentration of a copper(II) sulfate solution.
What is correct?
A A blue filter is used.
B A calibration curve of copper ion concentration against time is used.
C The absorption increases as the concentration of copper ions increases.
D The transmission decreases as the concentration of copper ions decreases.
Your answer [1]
11 Which statement about all sodium compounds is correct?
A They are less reactive than potassium compounds.
B They dissolve in water to give alkaline solutions.
C They form giant structures.
D They give a red flame test.
Your answer [1]
© OCR 2025
Section A
You should spend a maximum of 40 minutes on this section.
Write your answer to each question in the box provided.
1 Part of a protein structure can be represented as:
–CONHCH(CH3)CONHCH2CONHCH(CH3)–
What is correct about this part of the protein structure?
A All its amino acids show optical isomerism.
B It has three peptide links.
C It is an addition polymer.
D It is made from three different amino acids.
Your answer [1]
2 What is correct about the greenhouse effect?
A Greenhouse gas bonds vibrate more when warmed by infrared radiation.
B Greenhouse gases reflect infrared radiation back to Earth.
C The Earth emits mostly ultraviolet radiation.
D The principal radiation from the Sun is infrared.
Your answer [1]
3 An organic compound A is oxidised to a different compound which forms a silver mirror with Tollens’
reagent.
Which could be compound A?
A propanal
B propan-1-ol
C propan-2-ol
D propanone
Your answer [1]
© OCR 2025
, 3
4 Which statement about transition metals is correct?
A Copper(II) ions form an octahedral complex with chloride ions.
B Most manganese compounds have Mn in the oxidation state of +2, +4 or +7.
C Nickel is used as a catalyst in the hydration of alkenes.
D The dichromate ion is often used as a reducing agent.
Your answer [1]
5 Which statement about the element astatine, At, is likely to be correct?
A It displaces iodine from sodium iodide.
B It is a gas at room temperature.
C It is a weaker oxidising agent than chlorine.
D It is colourless.
Your answer [1]
6 Which of the following pairs can be structural isomers?
A acid anhydrides and aldehydes
B amines and amides
C carboxylic acids and esters
D diols and esters
Your answer [1]
7 Which row shows the correct electron configurations of Cr and Cr3+?
Cr Cr3+
A [Ar] 3d4 4s2 [Ar] 3d3
B [Ar] 3d4 4s2 [Ar] 3d1 4s2
C [Ar] 3d5 4s1 [Ar] 3d3
D [Ar] 3d5 4s1 [Ar] 3d1 4s2
Your answer [1]
© OCR 2025 Turn over
, 4
8 What is an advantage of both ethanol and hydrogen as alternatives to petrol?
A Their only product of combustion is water.
B They can be produced by fermentation.
C They do not produce nitrogen oxides in the engine.
D They do not produce oxides of sulfur on combustion.
Your answer [1]
9 What is correct about chlorine radicals in the atmosphere?
A They act as homogeneous catalysts that increase ozone depletion.
B They are formed by heterolytic fission of CFCs.
C They are formed by homolytic fission of CFCs by infrared radiation.
D They are heterogeneous catalysts that increase the rate of ozone formation.
Your answer [1]
10 A colorimeter is used to measure the concentration of a copper(II) sulfate solution.
What is correct?
A A blue filter is used.
B A calibration curve of copper ion concentration against time is used.
C The absorption increases as the concentration of copper ions increases.
D The transmission decreases as the concentration of copper ions decreases.
Your answer [1]
11 Which statement about all sodium compounds is correct?
A They are less reactive than potassium compounds.
B They dissolve in water to give alkaline solutions.
C They form giant structures.
D They give a red flame test.
Your answer [1]
© OCR 2025
